A battery cell has been proposed as a clean, efficient and environmentally responsible power source for electric vehicles and various other applications. One type of battery cell is known as the lithium-ion battery. The lithium-ion battery is rechargeable and can be formed into a wide variety of shapes and sizes so as to efficiently fill available space in electric vehicles. For example, the battery cell may be prismatic in shape to facilitate a stacking of the battery cells.
Typical prismatic battery cells have a pair of plastic coated metal layers fused around a periphery of the battery cell in order to seal the battery cell components. The sealing of the battery cell components generally begins with providing one of the plastic coated metal layers with a cavity, sometimes called a “butter dish” shape. The battery cell components are disposed inside the cavity of the plastic coated metal layer. The other of the plastic coated metal layers is then placed on top of the battery cell components and fused at the periphery to the one of the plastic coated metal layers with the cavity, for example, by heat sealing around the edges. The battery cell is thereby provided.
A plurality of individual battery cells can be provided in a battery pack to provide an amount of power sufficient to operate electric vehicles. Where the plurality of individual battery cells is employed, each of the battery cells may be disposed in a frame that cooperates with adjacent frames to align the battery cells in the battery pack. A typical frame is described in Assignee's co-pending U.S. patent application Ser. No. 12/651,640 to Weber et al., the entire disclosure of which is hereby incorporated herein by reference. The frame may include manifold apertures that define supply and exhaust manifolds for bulk transport of cooling fluid to and from cooling plates disposed between the individual battery cells. The frame may also include holes that cooperate with compression or tie rods to align and hold the battery cells in a stack to form the battery pack.
Typically, a plurality of external voltage sensing wires and wire harnesses is required to monitor a voltage of each battery cell within the battery pack. This arrangement is undesirable, as the voltage sensing wires carry high voltages and the number of voltage sensing wires and associated plugs increase a complexity of the battery pack. The external voltage sensing wires also undesirably impact a sealing of the battery pack, as the wires often extend between sealed interfaces between adjacent modules of the battery pack. Different designs for different frame assemblies within the battery pack are also often used in order to accommodate the large number voltage sensing wires and associated plugs.
There is a continuing need for a frame for a battery cell frame that permits voltage sensing without using external sense lead wires and wire harnesses in the battery pack. Desirably, the frame has sense lead wires integrated therein, minimizes a potential for exposure to high voltage wires and accidental plugging of external wires into incorrect wire harnesses, and provides a common design for all frames in order to minimize a number of parts needed in assembly of the battery pack and allow for a larger volume production of a single frame.